Epoxy anchor calculator

1. Drilled hole (in)
   a carbide bit drills the middle of its ANSI B212.15 range
   9/16" bit: ( 0.582 + 0.592 ) ÷ 2 = 0.5870
2. Threaded rod steel (in)
   rod − 5√3 ÷ 16 × thread pitch (halfway to the thread root)
   0.500 − 0.5413 × 0.0769 = 0.4584
3. Hole volume
   π ÷ 4 × drilled hole² × embedment
   π ÷ 4 × 9/16" ² × 4-1/2" = 1.22 in³
4. Just the gap
   hole − steel (π ÷ 4 × steel² × embedment)
   1.22 in³ − 0.74 in³ = 0.48 in³
5. Hole ⅔ full
   ⅔ × hole (the instructions say fill the hole about ⅔ full)
   ⅔ × 1.22 in³ = 0.81 in³
6. Epoxy per anchor
   (gap + ⅔ fill) ÷ 2
   ( 0.48 in³ + 0.81 in³ ) ÷ 2 = 0.64 in³
7. All anchors
   per anchor × anchors (+ tube), rounded up to a whole fl oz
   0.64 in³ × 20 = 8 fl oz
8. One cartridge gives
   cartridge less the nozzle and first-mix loss
   27.9 fl oz = 27.29 fl oz
9. Cartridges
   all anchors ÷ one cartridge, rounded up
   8 fl oz ÷ 27.29 fl oz = 1

Where the numbers come from

• Epoxy per anchor: Average of the gap (π ÷ 4 × (hole² − steel²) × embedment) and the hole ⅔ full (⅔ × π ÷ 4 × hole² × embedment)Installers fill the hole about ⅔ full; what the anchor pushes out of the hole is lost, so the real use is between the gap alone and the ⅔ fill — taken as the average of the two. The total is rounded up to a whole fl oz. Waste, if entered, is added on top for rough holes and hard conditions.
• Drilled hole size (ANSI B212.15): Carbide bit tips (in.): 7/16 0.458–0.468 · ½ 0.520–0.530 · 9/16 0.582–0.592 · ⅝ 0.650–0.660 · 11/16 0.713–0.723 · ¾ 0.775–0.787 · ⅞ 0.905–0.917 · 1 1.030–1.042 · 1⅛ 1.160–1.175 · 1⅜ 1.410–1.425 · 1½ 1.535–1.550A bit drills a little over its name; the hole is taken at the middle of the range (7/16 → 0.463, ⅞ → 0.911, 1½ → 1.5425). A hole size you type that is not a standard bit is used as typed.Source
• Threaded rod steel: d − 5√3 ÷ 16 × pitch: halfway between the outside of the rod and its thread root (d − 5√3 ÷ 8 × pitch) · UNC ⅜-16, ½-13, ⅝-11, ¾-10, ⅞-9, 1-8, 1¼-7Thread geometry (ASME B1.1, H = √3 ÷ 2 × pitch). The epoxy fills the thread grooves, so a rod holds less steel than a solid bar of its size (¾" → 0.6959", ½" → 0.4584"). Rebar uses its nominal size (#10 = 1.270").
• Extension tube: Past 8" deep: (embedment − 8") × 0.17 fl oz per inch, a new tube every 10 anchorsA mixing nozzle reaches about 8"; deeper holes are filled from the bottom through an extension tube, which holds 0.17 fl oz per inch (the inside of a ⅝" bore: π ÷ 4 × 0.625² = 0.307 in³ per inch) and is replaced every 10 anchors.
• Cartridges: Sizes in mL as printed, fl oz worked out (mL ÷ 29.5735) · Hilti HIT-HY 200 V3 330 / 500 mL = 11.2 / 16.9 fl oz · DeWalt AC100+ Gold 280 / 825 mL = 9.5 / 27.9 fl ozWhat a cartridge really gives, after the nozzle and the first mix: 9.07 fl oz from the 9.5 oz and 27.29 fl oz from the 28 oz AC100+ Gold. Hilti lists none, so its packs are taken at 96%.
• Hilti HIT-HY 200 V3: Bits: rod ⅜→7/16 · ½→9/16 · ⅝→¾ · ¾→⅞ · ⅞→1 · 1→1⅛ · 1¼→1⅜ · rebar #3→½ · #4→⅝ · #5→¾ · #6→⅞ · #7→1 · #8→1⅛ · #10→1½ · foil packs 330 and 500 mLHilti Anchor Fastening Technical Guide Ed. 22, Table 38 (threaded rod) and Table 18 (rebar); the same bits in grouted CMU (Masonry Anchor Design Guide 2023, Table 1); ICC-ES ESR-4868 (revised April 2026) §3.2.1 for the 330 / 500 mL packs. Hilti lists a bigger bit for deep embedment (#6 1", #7 1⅛", #8 1¼") — type it if you drill that deep. Hilti's own Volume Calculator is a phone app.Source
• DeWalt AC100+ Gold: Bits: rod ⅜→7/16 · ½→9/16 · ⅝→11/16 · ¾→⅞ · ⅞→1 · 1→1⅛ · 1¼→1⅜ · rebar #3→7/16 · #4→⅝ · #5→¾ · #6→⅞ · #7→1 · #8→1⅛ · #10→1½ · cartridges 280 mL (8478SD-PWR) and 825 mL (8490SD-PWR)DeWalt AC100+ Gold Technical Guide ©2025 rev. K (p. 2 installation, p. 29 ordering), matching ICC-ES ESR-2582 (Feb 2026) Table 9. Approved for rebar used as an anchor (embedment up to about 12 bar diameters), not for post-installed rebar development or splices.Source
• Hole size rule (the cross-check): Bit = anchor + adhesive ring, in 1/16" steps: rod + 1/16" up to ⅝", + ⅛" above · rebar (actual size) + ⅛" · every maker's bit is checked to leave 1/32"–3/16" of ring each sideA cross-check on every maker's bit, and the answer wherever a maker's number cannot be found. Makers may call for a different size — type your hole size if so.
• Method source: DeWalt Adhesive Anchor Volume EstimatorThe ⅔ fill, the extension tube and the usable cartridge follow it; every number on this page is also worked out by math.Source